Ovine trophoblast interferon enhances MHC class I expression by sheep endometrial cells

Type I interferons have a variety of important immunological functions, including effects on expression of class I molecules of the major histocompatibility complex (MHC). Interferon-tau (IFN-tau) is an important anti-luteolytic factor produced by the trophoblast of ruminants. Ovine endometrial cells were cultured with recombinant ovine IFN-tau and stained with monoclonal antibodies specific for ovine MHC class I molecules. The expression of MHC class I was then determined by immunocytochemical or immunofluorescent staining using microscopy or flow cytometry. IFN-tau was found to enhance the expression of MHC class I molecules on the endometrial cells, as did recombinant IFN-alpha. No significant effects on MHC class II expression were observed. These findings may have important implications for cellular interactions associated with immunological aspects of pregnancy.